So here is the recipe:
2 Cups whole milk
2 tbsp tarragon vinegar
4 large eggs, separated
1 medium size butternut squash (or 2 12-oz frozen, thawed packages)
1/3 cup parmesan cheese
1 cup white or yellow cornmeal
1 tsp baking powder
1 tsp chopped rosemary
1/2 tsp baking soda
1/4 cup butter, melted
1. Preheat oven to 350. At the same time, mix milk and vinegar and let sit for 15 minutes. Once milk mixture is ready, heat over medium heat for 4-6 minutes (until bubbly, but not boiling)
2. Lightly beat egg yolks in a large bowl; stir in squash and cheese. Combine cornmeal and next 4 ingredients in a small bowl. Stir cornmeal mixture into squash mixture. Pour warm milk over squash mixture and whisk until smooth. Let stand until luke warm (about 15 min).
3. Brush a 2.5-3 qt baking dish or 12 in cast iron skillet with butter or spray. Stir remaining melted butter into squash/cornmeal mixture.
4. Beat egg whites at high speed until stiff peaks form. Fold into squash mixture. Pour into baking dish.
5. Bake at 350 for 30-35 minutes.